This invention relates to a filter element for filtering a fluid stream comprising a fluid permeable, cylindrical supporting body having an outer surface and first and second end faces, and a filter medium surrounding the outer surface of the supporting body, and to an air filter comprising a housing with such a filter element disposed therein separating a housing inlet from a housing outlet.
German Patent application no. DE 37 23 807 discloses a tubular filter element formed by a rigid, radially perforated supporting tube, a filter medium and end disks. The outside of the supporting tube is covered by the filter medium. The end disks are made of plastic molded subsequently onto the supporting tube. The end disks seal the filter medium and thus affix the filter medium to the supporting tube.
It is known generally to cover supporting tubes with a prefabricated tubular filter medium. The filter medium may be sewn together, e.g., with a longitudinal seam, thus forming the tubular filter medium. This prefabricated tubular filter medium is pulled over the supporting tube in an assembly operation.
However, separate tubular filter media must be fabricated for each diameter of supporting tube, which results not only in a considerable logistical expenditure but also assembly costs and storage costs, In addition, many filter media in particular coated filter media in the prefabricated state,cannot be pulled over the supporting tube because they do not slide over the supporting tube.